Page 2 of 3

Re: Consulting the Metallurgy Oracle

Posted: Wed Oct 21, 2020 8:25 pm
by Tunborough
an seanduine wrote:Perhaps a tiny amount of silver. . .dropping the cost (at face value :D to 10 cents) by using a pre-1960´s dime?
The market for silver coins values them substantially higher than face value. Dropping a couple of 1960 dimes in would set him back over $2.

Re: Consulting the Metallurgy Oracle

Posted: Wed Oct 21, 2020 11:06 pm
by an seanduine
I like you, Tunborough :D You picked up on my snarky comment about face value without a ´snark´ emoji :D

:D Bob :D

Re: Consulting the Metallurgy Oracle

Posted: Thu Oct 22, 2020 1:05 pm
by Nanohedron
Tunborough wrote:
an seanduine wrote:Perhaps a tiny amount of silver. . .dropping the cost (at face value :D to 10 cents) by using a pre-1960´s dime?
The market for silver coins values them substantially higher than face value. Dropping a couple of 1960 dimes in would set him back over $2.
Well, and there's that. But in invoking cost-effectiveness I have to draw my line somewhere, or be stretched to the limit by distractions - and you guys are clearly enjoying giving the ol' rack a spin with Nano on it. I mean, sure, we can go the route of numismatologicationalities and take in the face vs. market value of hard-to-find vintage coins that I'm only somewhat more likely to stumble upon than to win the lottery; but instead of that, maybe we should bring up cost? At an average minting cost of 2¢ per penny, face value is something of a farce in the wrong direction. What's a taxpayer to do? Tear one's hair out (what's left of it) - that's what. So in terms of the much less glamorous topic of de-yucking a humidifier with coin of the realm as my medium, you'll forgive me if I stick with the mundane consensual fantasy under which a penny means 1¢ to the average consumer eyeing a pack of gum.

If I have to set base lines, then I reserve the right to be arbitrary. So there.

Re: Consulting the Metallurgy Oracle

Posted: Fri Oct 23, 2020 1:20 am
by david_h
Realm? :-?

Re: Consulting the Metallurgy Oracle

Posted: Fri Oct 23, 2020 1:25 am
by benhall.1
david_h wrote:Realm? :-?
Quite. :really:

Re: Consulting the Metallurgy Oracle

Posted: Fri Oct 23, 2020 11:45 am
by Nanohedron
benhall.1 wrote:
david_h wrote:Realm? :-?
Quite. :really:
Oh, fer ... remind me again: how is it that your land ever produced any poets at all?

Re: Consulting the Metallurgy Oracle

Posted: Fri Oct 23, 2020 2:55 pm
by david_h
Any unwanted electrical cables? Could strip the cores out.

Re: Consulting the Metallurgy Oracle

Posted: Fri Oct 23, 2020 3:15 pm
by Nanohedron
david_h wrote:Any unwanted electrical cables? Could strip the cores out.
There's a thought.

Re: Consulting the Metallurgy Oracle

Posted: Fri Oct 23, 2020 4:34 pm
by Nanohedron
an seanduine wrote:Perhaps a tiny amount of silver. . .
This pebble wouldn't get out of my shoe, so I wanted to know what sort of performance hierarchy there might be among antibiotic metals. Found this:

https://prism.ucalgary.ca/bitstream/han ... sAllowed=y

Definitely NOT light reading. But for layfolk (that includes me) the basic message is get-to-able, which is that evidently, copper is king. The study tests a range of metals for performance at inhibiting planktonic growth and biofilm in three different subjects - naturally E. coli was part of the selection - and copper's the generalist of the bunch. All the other metals - silver, titanium, gallium, nickel, aluminum and zinc - whatever their efficacy, behave selectively and often unequally. Only copper seems to do it all every time, and if it doesn't, it's close enough. And I was a bit surprised, because I had bet that nickel would easily be copper's equal as an agent of implacable bug-doom. Nope. With anything other than copper, you have to mix and match according to your target - sorta like grains with legumes if you want the complete protein ride. So, yeah - copper. Nice and simple.

Apparently all copper alloys - brass, bronze, etc. - display the same antimicrobial qualities of pure copper. As to strength, I didn't get that far. And I confess I'm surprised that copper-plated touch surfaces aren't faster becoming the norm in medical facilities. Sure, cost, but line-of-fire's something to invest in.

Re: Consulting the Metallurgy Oracle

Posted: Sat Oct 24, 2020 12:58 am
by david_h
That paper is about metal salts, ions in solution, not metallic surfaces. I had been wondering if your pennies had to be shedding ions to stop the gunk forming elsewhere. To hard to search for on the phone, but IIRC metallic copper’s effectiveness as a bug resistant surface is something to do with what its electrons do. Dunno if its the same in solution.

Re: Consulting the Metallurgy Oracle

Posted: Sat Oct 24, 2020 2:19 am
by benhall.1
Nanohedron wrote:
benhall.1 wrote:
david_h wrote:Realm? :-?
Quite. :really:
Oh, fer ... remind me again: how is it that your land ever produced any poets at all?
By having poets who speak truth.

Re: Consulting the Metallurgy Oracle

Posted: Sat Oct 24, 2020 1:27 pm
by Nanohedron
david_h wrote:... IIRC metallic copper’s effectiveness as a bug resistant surface is something to do with what its electrons do. Dunno if its the same in solution.
I see. Very possibly ions, then. The practical point for me, your average Joe on the street, is that whether the agent be electrons or salts, copper appears to have a reasonably consistent antibiotic effect all around. More than once I've heard the story of the havoc that exposed copper wreaks on pet fish in a tank - it's usually a penny dropped in by some unprincipled joker - and humidifier tanks also being an aqueous environment, I thought it was quite reasonable to see if pennies might do the same with planktonic growth. And so it appears to be. It also invites us to consider taking a certain amount of care in how we use copper long-term; no doubt a copper bracelet's going to be okay, but I won't be swallowing whole pennies any time soon.
benhall.1 wrote:
Nanohedron wrote:... how is it that your land ever produced any poets at all?
By having poets who speak truth.
I confess that given the thrust of my question, your equation escapes me.

Re: Consulting the Metallurgy Oracle

Posted: Sat Oct 24, 2020 1:53 pm
by an seanduine

Re: Consulting the Metallurgy Oracle

Posted: Sat Oct 24, 2020 2:35 pm
by Nanohedron
an seanduine wrote:Just to add: https://www.smithsonianmag.com/science- ... 180974655/

Bob
Thanks for that. It better explains the electrons-vs-ions question; apparently the electrons facilitate, but it's ions that do the work, even with dry contact. The following, I think, is particularly notable:
Most importantly, the ions seek and destroy the DNA and RNA inside a bacteria or virus, preventing the mutations that create drug-resistant superbugs.
That should be a selling point right there.

So anyway, I decided I might as well add the copper scrubbie to my arsenal of dishwashing paraphernalia, and gave it a run yesterday; I'd never used one before. It worked a treat, but during use the copper smell seems to amplify and change somewhat for the worse, and it's a bit intrusive. We'll see if I stick with it.

Re: Consulting the Metallurgy Oracle

Posted: Sat Oct 24, 2020 3:52 pm
by an seanduine
That´s ´cuz the friction on the scrubbie is throwing off free ions and they are tickling you schnoz receptors. . . :D
It´s all good. :D

Bob